This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Yes, you can, but not recommended. If u decide to go this way you may use POJO classes as DAO objects and build facade session beans to access them. You may also build BMP entity beans or eve use a persistent framework as Hibernate to get to the DB. regards.